Seam-trimming mechanism for sewing-machines.



E. B. ALLEN.

SEAN: TRIMMING MECHANISM FOR SEWING MACHiNES. APPLICATION FILED 020.30.1913.

1,234,996. Patented July 31, 1917.

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A TTOR/V E Y E. B. ALLEN.

SEAM TRIMMING MECHANISM FOR SEWING MACHINES- APPLICATION FILED DEC-30.1.9131.

1,234,996. Patented July 1.917.

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By Wm Y ATTORNEY UNITED STATES PATENT OFFICE.

EDWARD B. ALLEN, OF BRIDGEPOBT, CONNECTICUT. ASSIGNOR TQ THE SINGER MANU- FACTURING COMPANY, A CORPORATION OF NEW JERSEY.

SEAM-TRIMMIN'G MECHANISM FOR SEWING-MACHINES.

Specification of Letters Patent.

Application filed December 30, 1913. Serial No. 809,459.

To all whom it may concern:

Be it known that I, EDWARD B. ALLEN, a citizen of the United States, residing at Bridgeport, in the county of Fairfield and State of Connecticut, have invented certain new and useful Improvements in Seam- Trimming Mechanisms for Sewing-Machines, of which the following is a specification, reference being had therein to the accompanying drawings.

This invention relates to improvements in seam-trimmers for sewing machines and has for its object to provide a durable construction convenient of adjustment and applicable to machines'employing loop-takers having stitch-forming movements in either a vertical or a horizontal plane, and so combined and operated that the trimmer-blade guard will, under all conditions of operation, occupy a position parallel with the cutting edge of the ledger trimmer-blade.

The present device is more particularly adapted to the requirements of a loop-taker operated in a horizontal plane and provided with a bobbin which has to be displaced in replenishing the under thread, as in such constructions the space between the cutting edge of the ledger-blade and the. periphery of the bobbin is not sufiicient to accommodate the commonly employed pivotally mounted trimmer-blade guard and it is believed that the present construction effects a variety of seam trimmer sewing machine new to the art.

Referring to the drawings, Figure 1, is a view in front end elevation of the bed-plate. and certain other parts later to be referred to, of a sewing machine fitted with the present seam-trimming device, Fig. 2, a. plan view of Fig. 1 with the parts overhanging the bed-plate omitted. Figs. 3, 4, 5 and 6 are plan views of the seam-trimmer base-plate; needle-plate and ledger trimmer-blade; needle-plate carrier and trimmer-blade guard and guard guideways, respectively.

The present invention is shown as applied to one form of commonly employed commercial sewing machine, substantially such as is represented by U. S. Patent, No. 722,496, dated March 10, 1903, to Dimond and Dial, and as this machine is similar in construction to all machines of its class only such details are herein illustrated as is deemed necessary for an understanding of the invention.

Referring to the figures, 1 represents the sewing-machine bed-plate, 2 the loop-taker carried by the loop-taker shaft 3 mounted in suitable bearings, as 4, formed in the adjustable frame or saddle 5 secured by screws, as 6 to the bed-plate 1, the shaft 3 being operatively connected with the main shaft 7 by suitable spiral gears, as 8, said looptaker being provided with the usual bobbin 9. 10 represents the feed-dog carrying bar provided with the commonly employed fourmotion feed-dog 11, said bar being connected at one end by a link 11 (shown in dotted lines only, Fig. 1) with the feed rockshaft 12, the opposite end being connected, through a slide-block 13 and crank-arm 14, with the feedl ift rock-shaft 15. 16, represents the machine needle. 17 the clothpresser carrying bar provided with the cloth-presser 18, and 19 represents the seamtrimmer blade.

20 represents the seam-trimmer base-plate mounted in suitable guide-ways, as 21, formed in the bed-plate and adjustably secured with respect to the latter by screw 22 passing through the opening 23 and threaded into said bedplate, 24 the needle plate provided with an opening 25 for the reception of the feed-clog 11, said needle-plate having formed integral with it a ledgerblade 26 provided with a needle opening 27, 28 is the needle-plate carrier to which the needle-plate is secured by screws, as 29, the carrier being provided with an opening 30 corresponding to and registering with the opening 25 formed in said needle-plate, the opening 31 in the carrier being provided to accommodate the vertical movement of the trimmer-blade 19 and the opening 32 to accommodate the stitch-forming movements of the needle. The needle-plate carrier and its guide-ways, as 33, are secured upon the base-plate 20 by screws, as 34, passing through openings, as 35, and threaded into the openings, as 36, in said baseplate. While the making of the ledgerblade integral with the needle-plate comprises a preferred form of construction it is to be understood that they might comprise separate elements without materially changing the nature of the construction.

37 represents the trimmer-blade guard;

Patented July 31, 1917.

plate slidably mounted in the guide-ways, as 33, and provided with a trimmer-blade guard 38, the springs, as 39, seated in said guard-plate and acting against the wall 40 of the needle-plate, acting to hold the free edge of said trimmer-blade guard in contact with said trimmer-blade to resiliently force the cutting edge of the latter in contact with the like edge of the ledger-blade 26. The inner edges or walls, as 41, of the guardplate are beveled to force upward any fibers or cuttings resulting from the trimming operation.

In the trimming operation the trimmerblade is given vertical movements in a manner common to earlier constructions substantially the same as is represented by United States Patent No. 568,896, of October 6, 1896, to Dimond and Dial, the depending lug 42 of the trimmer-blade being mounted in the notch 43 formed in one of the walls 41 of the guard-plate 37 and entering the opening 31 in the carrier-plate 28.

Having thus set forth the nature of the invention, what I claim herein is 1. A trimming mechanism for sewing machines employing a feeding mechanism and a rotary loop-taker having stitch-forming movements in substantially a horizontal plane and provided with a centrally arranged bobbin receiving space, said trimming mechanism comprising a trimmerblade, a ledger trimmer-blade and a trimmer-blade guard, the latter being located at the same side of the line of feed actuation as said loop-taker and out of Vertical alinement with said bobbin receiving space to permit of the convenient replenishing of the latter.

2. A trimming mechanism for sewing ma chines employing a feeding mechanism and a rotary loop-taker having stitch-forming movements in substantially a horizontal plane and provided with a centrally arranged bobbin receiving space, said trimming mechanism comprising a trimmerblade, a ledger trimmer-blade and a trimmer-blade guard, the latter and said trimmer blades being located intermediate the line of feed actuation and said bobbin re ceiving space to permit of the convenient replenishing of the latter.

In testimony whereof, I have signed my name to this specification, in the presence of two subscribing witnesses.

EDWARD B. ALLEN. Witnesses ARTHUR J. HALE, STANLEY N. SMITH.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. G. 

